EA - IT Architecture V2 > Architecture Specification > Describing information exchanges > Managing Service Interactions > Describing Service and Request Points
Describing Service and Request Points
In a service-oriented architecture, communication is based on access points: service points and request points.
*A request point is a point of exchange by which an agent requests a service from potential suppliers.
*A service point is a point of exchange by which an agent offers a service to potential customers.
Service points  
An application system, for example, is created to ensure one or more services. These services are represented by service points.
*A service point is a point of exchange by which an agent offers a service to potential customers.
The service is requested according to precise terms defined by a service interface assigned to the service point.
*A Service Interface is a template of a contract between entities (organizational, IT …). The contract is described by available operations which can be triggered trough messages exchanged by roles (vendor, buyer..).
*For further detail on service interfaces, see Describing a service interface.
Components activated to assure a service are linked to the service point by service interactions. If it is necessary to activate several components, you have to create several service interactions between the service point and the system components.
In the example presented here, the IT Service ”Customer Management” is activated by the interaction service “Information request”.
*To create a service point, see Creating a Service Point or a Request Point.
*The Published Fulfillments property page of the service point enables the access to the capabilities implemented by the service point that interests you. To create a service point, see Access to implementations from a service point.
Request points 
A request point enables representation of use of a service external to the described entity.
*A request point is a point of exchange by which an agent requests a service from potential suppliers.
The service is requested according to precise terms defined by a service interface assigned to the request point.
*A Service Interface is a template of a contract between entities (organizational, IT …). The contract is described by available operations which can be triggered trough messages exchanged by roles (vendor, buyer..).
*For further detail on service interfaces, see Describing a service interface.
Components that issue a request are linked to the request point by a service interaction.
In the example, request points represent requests for service executed by the “Email Order Management" IT service to identifier a customer and issue an order.
*To create a request point, see Creating a Service Point or a Request Point.
Creating a Service Point or a Request Point 
The process for creating a service point or request point is identical.
*A request point is a point of exchange by which an agent requests a service from potential suppliers.
*A service point is a point of exchange by which an agent offers a service to potential customers.
To create a service point:
1. In the diagram insert toolbar, click Service Point .
2. Position the object at the edge of the frame of the described object.
A creation dialog box opens.
3. Click the arrow to the right of the Service Interface field to define the service interface enabling activation of this service point, and select, for example, Connect Service interface.
A query window opens.
4. Select the service interface associated with this service point and click Connect.
5. Click Next.
A dialog box opens proposing a list of the service interface roles that can be associated with the service point.
*This dialog box is not proposed if there is only one candidate role that can be associated with the service point.
6. Select the role that interests you and click OK.
The service point appears in the diagram.
Defining the Element Interaction Point
The interaction point of an element connects a service interaction to one of the components in communication. This specifies:
• on the one hand, the service point, or the request point, that intervenes in the communication
• on the other hand, the role, consumer or supplier represented by the interaction point in service interface. The graphic representation of the interaction point gives indications on the role.
The interaction point is connected to an element playing the supplier role in service interface.
The interaction point is connected to an element playing Consumer role in the service interface.
Accessing characteristics of an element interaction point 
To access the properties of an element service point or request point:
1. Open the properties of the element concerned; for example an application.
2. Select the Components page and Boundary Components section.
3. Select the tab corresponding to the service point or request point that interests you.